For thousands of years, mankind has known that wheels can make a job easier. What may seem to be an easy job — pushing, pulling and manoeuvring food manufacturing equipment or service carts — can easily tire out the best of employees.

Therefore, the type of casters and wheels on equipment — such as mixing machines, slicers, bakery equipment, conveyors and material handling equipment — make all the difference in the world. A day in the life of a caster will see it roll from a central supply depot, where it would be travelling over a smooth corridor, then over tile flooring in a kitchen or cafeteria, to rolling into a high-temp bakery oven, and end up in a flash freezer. So what’s the best choice of casters and wheels in the food manufacturing and processing industry?

Choosing the right caster requires an assessment of the load to be moved, the condition of the floor surface and the range of hot to cold environments in which the casters are operating. As well, ergonomics, ease of maintenance, noise and composite materials are important considerations.

The rated load of a caster is the maximum weight that may be imposed on it for manual operation. The weight includes the cart system or equipment and its total load to be transported. The load per caster is calculated as total gross load divided by the number of casters affixed to the cart or equipment (minus the number of casters that may not be in contact with the ground while the cart is in motion over uneven floor conditions). For example, minimum loads of 250 pounds per caster will suffice for most bakery cart racks. This translates into a fully loaded cart of up to a thousand pounds being pushed and pulled all day long. On the other hand, dough-mixing equipment may require loads in excess of 3,000 pounds in total, so each caster should have the capacity of at least 900 pounds.

Having satisfied the load capacity per caster, what about the wheels? In general, the selection criteria include the choice between hard or soft tread wheels, and having flat surface or crown tread profile. Bearing choices include sealed precision ball, plain delrin or bronze bearing, roller bearing, and the need for stainless-steel hardware since the application is the food processing industry.

Precision sealed bearings are not only maintenance free (whereas all other bearings require some food-grade lubrication) but facilitate lower resistance force required to start and keep rolling the carts and equipment on any floor condition. As well, wheels with precision bearings minimize downtime.

Harder wheels roll easier, but tend to emanate more noise than softer tread wheels. Crown tread profile wheels manoeuvre more easily than flat tread wheels. Newer composite materials now available in the market offer both the rolling ease of hard tread wheels, along with the quick, quiet, and clean, properties of soft tread wheels that require no maintenance. Wheel and bearing selections are intertwined. The better the choice of wheels to be used, the more the ergonomic needs of the employees are fulfilled in pushing, pulling and manoeuvring food equipment, conveyors, carts and mobile tumbler mixers.

The optimal choice of caster for the food-equipment industry is stainless-steel frames with no lubricant (hot or low-temperature grease). This not only satisfies all types of application uses but facilitates wash-down conditions as well as the ability of the casters to equally function in harsh-heat or flash-freeze environments. The stringent requirements in the food processing industry necessitate that better wheels and bearings be utilized so as to optimize operational use, while also meeting the suitability of NSF listing.

Other considerations in caster selection include functionality of wheel brake, swivel lock, or both; foot operated directional lock; integrated tread guards; and mounting options.

When Ezekiel invented the wheel some 3,500 years ago in the hills of Mesopotamia, he would have had no idea how critical it would become in day-to-day in the food industry.

They are now integral elements on food manufacturing equipment, bakery carts and related applications in the food processing environments, keeping companies on a roll.

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Mike Titizian is president of Colson Caster Ltd. in Cambridge, Ont. For more information, visit www.colson.ca. This was originally published in the April 2010 Food & Beverage Engineering & Maintenance supplement.